Restrictive and/or obstructive implant system for inducing weight loss

ABSTRACT

The present application describes an implant system useable for positioning an implant device such as a device useful for restricting passage of ingested food into the stomach. In one embodiment, the disclosed system includes a plurality of anchors that may be coupled to tissue within the stomach, or to a tissue tunnel formed by plicating stomach wall tissue. The anchor includes a loop. During use, the implant device is inserted through the loop and expanded such that it retains its position within the loop until removed. Instruments for implanting and explanting the implant device are also described.

PRIORITY

The present application is a divisional of U.S. patent application Ser.No. 11/439,461, filed May 23, 2006, now pending, which claims thebenefit of U.S. Provisional Application No. 60/683,635, filed May 23,2005; and U.S. patent application Ser. No. 11/439,461 is also acontinuation-in-part of U.S. patent application Ser. No. 10/575,222,filed Apr. 10, 2006, now pending, which is a continuation ofPCT/US2004/033007, filed Oct. 8, 2004, which is a continuation-in-partof U.S. patent application Ser. No. 10/843,702, filed May 11, 2004, nowabandoned, which claims the benefit of U.S. Provisional Application No.60/510,268, filed Oct. 10, 2003, U.S. patent application Ser. No.10/575,222 is also a continuation-in-part of U.S. patent applicationSer. No. 10/898,036, filed Jul. 23, 2004, now U.S. Pat. No. 7,431,725,which claims the benefit of U.S. Provisional Application No. 60/510,268,filed Oct. 10, 2003.

FIELD OF THE INVENTION

The present invention relates generally to the field of implants forinducing weight loss in patients, and specifically to devices andmethods for reducing the effective volume of a patient's stomach and/orcreating restrictions to slow passage of food into the stomach.

BACKGROUND OF THE INVENTION

An anatomical view of a human stomach S and associated features is shownin FIG. 1A. The esophagus E delivers food from the mouth to the proximalportion of the stomach S. The z-line or gastro-esophageal junction Z isthe irregularly-shaped border between the thin tissue of the esophagusand the thicker tissue of the stomach wall. The gastro-esophagealjunction region G is the region encompassing the distal portion of theesophagus E, the z-line, and the proximal portion of the stomach S.

Stomach S includes a fundus F at its proximal end and an antrum A at itsdistal end. Antrum A feeds into the pylorus P which attaches to theduodenum D, the proximal region of the small intestine. Within thepylorus P is a sphincter that prevents backflow of food from theduodenum D into the stomach. The middle region of the small intestine,positioned distally of the duodenum D, is the jejunum J.

FIG. 1B illustrates the tissue layers forming the stomach wall. Theoutermost layer is the serosal layer or “serosa” S and the innermostlayer, lining the stomach interior, is the mucosal layer or “mucosa”MUC. The submucosa SM and the multi-layer muscularis M lie between themucosa and the serosa.

Prior art treatments for obesity range from diet and medication tohighly invasive surgical procedures. Some of the more successfulsurgical procedures are the vertical banded gastroplexy or the proximalgastric pouch with a Roux-en-Y anastomosis. However, known complicationsare present with each of these procedures. More successful and lessinvasive options are desired.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1A is a schematic illustration of a human stomach and a portion ofthe small intestine.

FIG. 1B is a cross-sectional perspective view of a portion of a stomachwall, illustrating the layers of tissue forming the wall.

FIG. 2 is a side elevation view of one embodiment of an implant system,including an endoscope, delivery tool, implant, and anchor.

FIG. 3A is a schematic illustration of a human stomach illustrating atissue tunnel formed at the gastro-esophageal junction region of astomach.

FIG. 3B is a cross-section view of the tissue tunnel of FIG. 3A, takenalong the plane designated 3B-3B.

FIG. 3C is a cross-sectional perspective view of a portion of stomachwall, showing another type of tissue tunnel that may be used.

FIG. 3D is a cross-sectional top view of a stomach showing three suchtissue tunnels in tissue plications formed on the wall of a stomach.

FIG. 4A is a cross-section view of a stomach taken along the planedesignated 4A-4A in FIG. 3A and further illustrating retention of twoanchors of the type shown in FIG. 2 within the tissue tunnels.

FIG. 4B is a cross-section view similar to FIG. 4A showing analternative arrangement of two anchors of the type shown in FIG. 2within the tissue tunnels.

FIG. 4C is a perspective view of an alternative embodiment of an anchor.

FIG. 4D is a cross-section view similar to FIG. 4A showing a secondalternative embodiment of an anchor.

FIG. 5A is a side elevation view of an implant in the radially expandedposition.

FIG. 5B is a side elevation view of the implant of FIG. 5A in thestreamlined implantation position.

FIG. 5C is a cross-sectional side elevation view of all implantpositioned within a stomach.

FIG. 6 is a perspective view of an alternative embodiment of an implant.

FIG. 7 is a cross-sectional side elevation view of a second alternativeembodiment of an implant.

FIGS. 8A through 8F are a sequence of drawings illustrating a method forforming a tissue tunnel of the type shown in FIG. 3A on the wall of astomach.

FIG. 9A is a cross-sectional view similar to FIG. 4A showing use of athird alternative embodiment of an anchor. Two such anchors are shownconnected to two plications formed in the stomach wall.

FIG. 9B is a cross-sectional side view taken along the plane designatedby 9B-9B in FIG. 9A.

FIGS. 10A through 10F are a sequence of drawings illustrating use of thesystem of FIG. 2 to position an implant.

FIGS. 11A and 11C are a sequence of drawings illustrating use of thesystem of FIG. 2 to remove an implant.

FIG. 12 is a cross-section view similar to FIG. 4A illustrating a fourthalternative anchor embodiment.

FIG. 13 illustrates use of the anchor of FIG. 12 to support an implant.

FIG. 14 illustrates use of the anchor of FIG. 12 to support analternative implant.

FIGS. 15A through 15D are a sequence of cross-section views of a stomachillustrating a method of re-shaping tissue to form a circumferentialplication, and using the circumferential plication to retain an implant.

FIGS. 16A through 16C are a sequence of cross-section views illustratinga modification to the method shown in FIGS. 15A through 15D.

DETAILED DESCRIPTION

The drawings show a number of implants intended to induce weight loss inone or more of a variety of ways, as well as anchoring devices thatsupport such implants within the stomach.

For the purposes of this application, the terms “restrictive devices”,“satiation devices,” or “obstructive devices” will be used to meanimplants intended to induce weight loss in one or more of a variety ofways. These include, but are not limited to, slowing the rate at whichfood passes from the esophagus into the stomach, physically restrictingthe amount of food that can be consumed, effectively reducing thestomach volume, and/or imparting pressure against portions of the GIsystem (e.g. stomach, esophagus, esophageal sphincter, etc.) causing thepatient to experience sensations of fullness, and/or affecting levels ofhormones or other substances in the body that control or affect feelingsof hunger, and/or affecting the amount of ingested food absorbed by thebody. The anchoring devices and methods described herein are useful forvarious types of satiation implants, including those not specificallydescribed herein and including those positionable in the esophagus, thegastro-esophageal junction region and other portions of the stomachincluding the proximal stomach, fundus, antrum, etc.

The devices may be provided in one or more kits, which may furthercomprise instructions for use according to any of the implantationand/or retention methods described herein. Optionally, such kits mayfurther include any of the other system components described in relationto the devices and associated methods, and any other materials or itemsrelevant to those devices and methods. For example, kits may includeendoscopic or laparoscopic stapling, suturing and/or cuttinginstruments, guidewires, positioning mandrels, and any other toolsneeded to carry out the procedure.

It should be noted that although the embodiments are described in thecontext of satiation devices, certain of the described components andmethods might be equally suitable with other types of implants. Theseimplants include, but are not limited to prosthetic valves for thetreatment of gastro-esophageal reflux disease, gastric stimulators, pHmonitors and, drug eluting devices that release drugs, biologics orcells into the stomach or elsewhere in the GI tract. Such drug elutingdevices might include those which release leptin (a hormone whichcreates feelings of satiety), Ghrelin (a hormone which creates feelingsof hunger), octreotide (which reduces Ghrelin levels and thus reduceshunger), Insulin, chemotherapeutic agents, natural biologics (e.g.growth factor, cytokines) which aid in post surgery trauma, ulcers,lacerations etc. As yet another example, the implant may provide aplatform to which specific cell types can adhere, grow and providebiologically-active gene products to the GI tract. As otheralternatives, an implant may provide a platform for radiation sourcesthat can provide a local source of radiation for therapeutic purposes,or provide a platform whereby diagnostic ligands are immobilized andused to sample the GI tract for evidence of specific normal orpathological conditions, or provide an anchor point for imaging the GItract via cameras and other image collecting devices.

It should also be noted that certain embodiments described herein haveapplicability for retaining implants in parts of the body outside the GIsystem. Thus, the term “implant” will thus be used to refer to satiationdevices as well as other types of medical devices that may be implantedin the esophagus, gastro-esophageal junction, stomach, elsewhere withinthe GI tract, or in other hollow organs, vessels, and cavities of thebody.

FIG. 2 shows one embodiment of an implant system 10 for inducing weightloss. System 10 includes a satiation implant 12, and one or more anchors14 for supporting the implant within a stomach, such as in the region ofthe gastro-esophageal junction, and a delivery tool 16 for use inintroducing and positioning the implant 12. System 10 may optionallyinclude an endoscope 18, which may be one of various endoscopesavailable for use in endoscopic procedures.

Anchor 14 includes a fastener 20 and a loop 22. Fastener 20 serves as acoupling device that enables the anchor to be coupled to a tissuestructure within the stomach. It is preferably a C-bar type fastener andincludes male and female connectors 24, 26 that engage with one anotheras indicated by arrows in FIG. 2. Referring to FIG. 3A, fastener 20 isproportioned to be suspended from a tissue tunnel 28 formed usingstomach wall tissue as will be discussed in more detail in connectionwith FIGS. 8A through 8F. During implantation of the anchor, oneconnector 24 of fastener 20 is preferably threaded through the tissuetunnel 28 and engaged with the other connector 26 to form the fastenerinto a loop encircling a portion of the tissue tunnel. This isadvantageous in that the anchor 14 may be coupled to the tissue withoutpenetration of the mucosal tissue by the anchor 14 or associatedsutures, staples, etc., although such penetration may be used ifdesired. Anchor 14 may be formed of a flexible material that willwithstand the acidic environment of the stomach. Examples of suchmaterials include, but are not limited to polyesters (e.g. Dacron®polyester), ePTFE fabric (e.g. GoreTex® fabric or others), a urethanessuch as ChronoFlex® polyurethane, nylon fabrics, silicone, otherpolymeric materials.

The anchor 14 may be used alone or in combination with one or moreadditional anchors. As illustrated in FIG. 4A, in a first embodiment twoor more of such anchors 14 are positioned in separate tissue tunnels 28,with the loops 22 of the anchors 14 roughly aligned with one other. Thisarrangement allows the anchors to be independent of one another so as tominimize tensile forces between the anchors in response to movement ofthe stomach walls. Alternatively, the anchors may be interconnected. Forexample in the arrangement shown in FIG. 4B, the anchors are positionedwith the male connector 24 of each anchor coupled to the femaleconnector 26 of the other anchor. In a variation of this embodiment, asingle anchor may be used in which a single loop (similar to loop 22) isprovided with two or more fasteners 20 connected to it. In either ofthese latter embodiments, an element of play can be built into the loopso as to minimize tensile forces between the fasteners. For example, asshown in FIG. 4C, the loop 22 a may be formed of mating components thatslide relative to one another in response to movement of the stomachwalls.

FIG. 4D illustrates yet another alternative anchor 14 b in which theanchor 14 b is formed of a flexible elongate band having mating elementssuch as connectors 24 b, 26 b. This anchor 14 b may be implanted byfeeding one end of the band through two or more tissue tunnels 28 in amanner which forms a portion of the band into a loop 22 b as shown. Thesections of the band forming the loop may lie on top of one another asshown in FIG. 4D, or they may be intertwined.

Referring again to FIG. 2, implant 12 is proportioned to be securelyheld within the loop 22 of the anchor 14. In one embodiment, implant 12includes a relatively narrow waist section 30 situated between an oradsection 32 and an aborad section 34. With this arrangement, the loop 22of anchor 14 can engage the waist section 30 as described with respectto FIGS. 10E-10F so as to support the implant 12 within the stomach.

Referring to FIGS. 2 and 5A, implant 12 preferably includes a an oradring 36 surrounding an orad opening 136 and an aborad opening 138surrounded by ring 38. The waist section 30 may include a ring similarto rings 36, 38.

A passageway 40 ends between the openings 136, 138. Passageway 40 allowsfor access by an endoscope and other instruments as detailed in theImplantation section below. The implant 12 may be hollow, in which casethe passageway 40 may be continuous with the hollow interior of theimplant. Alternatively, the implant may be toroidal, with the passagewayforming the central opening of the toroid (see FIG. 6).

Implant is preferably made of a flexible, self expandable, materialsuitable for use within the stomach. Examples include polyesters (e.g.Dacron® polyester), ePTFE fabric (e.g. GoreTex® fabric or others),urethanes such as ChronoFlex® polyurethane, nylon fabrics, silicone,latex, or other polymeric materials. As shown in FIG. 5A, implant 12 mayinclude a frame 42 (e.g. which may be formed of a mesh, strut elements44 and/or other features). The frame is preferably manufactured usingnitinol or shape memory polymers to facilitate self-expansion of theimplant. Frame 42 may be provided with a covering or coating formed ofDacron® polyester, silicone, urethanes or other material, or it may beprovided without a covering or coating. The implant materials aresufficiently flexible to allow the implant 12 to be manipulated to astreamlined position, such as by applying tension between the oradsection 32 and the aborad section 34 as shown in FIG. 5B, or bycompressing the implant radially inwardly. The waist 30 and the rings36, 38 and may include small holes 31, 37 and 39, respectively, forreceiving wires, sutures, or other elements that may be used to anchorthe implant 12 on an implantation tool.

The shape and dimensions of the implant 12 are selected to induce weightloss by restricting patient eating in one or more ways. For example,referring to FIG. 5C, the implant 12 may be contoured such that when theorad section 32 is positioned in close proximity to the surroundingwalls of the gastro-esophageal junction region, very little food canpass around the implant 12, and the dimensions of the passageway 40restrict the amount of food that can pass through the passageway 40 atone time. Thus, the restrictive and obstructive nature of the deviceslows passage of food from the esophagus into the stomach, and preventsthe patient from eating large quantities of food. In variousembodiments, the dimensions of the passageway 40 may be selected basedon the amount of flow restriction needed for the patient. In otherembodiments, the passageway 40 may be sealed, extremely narrow, orabsent from the implant so as to cause all ingested food to eventuallyflow around the limited space around the perimeter of the implant.

The implant preferably includes soft, atraumatic edges in regions thatmight contact the surface of stomach mucosa, to prevent irritation ofthe tissue. In one alternative embodiment, the outer profile of theimplant may be spherical or semi-spherical such that the device can rollover the stomach surface during movement of the stomach.

In an alternative implant 12 a shown in FIG. 6, the surface of oradsection 32 a is substantially flat. The aborad section 34 a may becurved as shown, or it may be flat.

FIG. 7 shows an alternative embodiment of an implant 12 b whichfunctions as a space occupier in addition to or as an alternative torestricting flow of food from the esophagus to the stomach. In the FIG.7 embodiment, the aborad section 34 b is sufficiently large to occupysufficient space within the stomach to create feelings of satiety and/orto reduce stomach capacity. In some embodiments, the implant 12 b mayhave an expanded volume in the range of approximately 200-700 cc,sufficient to fill a portion of the stomach, thereby causing the patientto feel full and thus limiting food intake. Implant 12 b may beinflatable, and it may include an inflation port 46 or a region ofself-sealing material, either of which may be engaged by an inflationtube introduced into the stomach after the implant is positioned.

The FIG. 7 embodiment may be positioned at various locations within thestomach. For example, it may be positioned in the gastro-esophagealjunction region or the fundus where it may function to occupy space soas to reduce effective stomach volume, but also to create a restrictionwhich can restrict the rate at which food can descend from the esophagusinto the stomach as discussed with prior embodiments. Alternatively, itmay be positioned in the antrum A or the pylorus P (FIG. 1A) to reducethe effective stomach volume and/or to slow the exit of food from thestomach into the intestines.

Referring again to FIG. 2, implantation tool 16 for the implant 12 ofFIG. 2 includes an outer shaft 15, a middle shaft 17 and an inner shaft19. Outer shaft 15 is arranged to receive the orad section 32 of theimplant and may include a broadened mount 21 to facilitate seating ofthe orad ring 36 on the shaft 15. Similarly, inner shaft may also have amount 23 for receiving the aborad section 34 of the implant 12, andmiddle shaft 17 might also include a mount 25 for accommodating thewaist section 30 of the implant 12. Shafts 15, 17, 19 are slidabletelescopically relative to one another. Thus, the shafts may be moved toan expanded position to spread the mounts 21, 23, 25 relative to oneanother and to thus elongate the implant into the streamlinedorientation shown in FIG. 5B. Similarly, the shafts may be adjusted toclose the spacing between the mounts 21, 23, 25, thereby allowing theimplant to assume its natural orientation.

Retraction of the shafts may be actuated using release tabs 43 a, 43 bon the handle of the implantation tool. For example, the implantationtool 16 may include spring loaded latches (not shown) that retain thetool in the expanded position and that are disengaged using the releasetabs 43 a, 43 b. Thus, for example, depression of release tab 43 a willrelease the latch associated with outer shaft 15, thus causing the outershaft to slide distally relative to the middle shaft 17. Similarly,actuation of release tab 43 b will disengage the latch associated withinner shaft 19 so as to allow the inner shaft to slide proximallyrelative to the middle shaft. In this embodiment, movement of the shaftsupon release of the latches may be spring biased or manual.

Small holes 27 a, b, c may be formed in each of the shafts 15, 17, 19for receiving wires, sutures, or other elements that may be used toanchor the implant 12 on the implantation tool 16.

Alternative implantation tools may rely on other mechanisms fordelivering the implant to the desired location. For example, alternativetools may include retractable elements for grasping portions of theimplant (e.g. the rings or loops such as the loops 84, 86 shown in FIG.11A) and then releasing the implant when it is the proper position.Alternative embodiments may also rely solely on the shape memoryproperties of the implant for expansion of the implant within the body.

Anchor Implantation

Exemplary methods for implanting anchors 14 will next be described.

In a preferred method, tissue tunnels 28/28 a (FIGS. 3A-3C) are formedto provide an anatomical structure on the stomach wall to which theanchors 14 may be coupled. The tunnels may be formed using laparoscopic,endoscopic, and/or surgical approaches. Various procedures for formingtissue s/tunnels are described in Applicant's prior application WO2005/037152, entitled “Devices and Methods for Retaining aGastro-Esophageal Implant” published Apr. 25, 2002, which is commonlyowned with the present application and which is incorporated herein byreference.

As discussed in the prior application, tissue tunnels may be createdusing tissue plications formed by grasping sections of tissue andstapling or suturing the tissue together to form tissue structures. Suchstructures may be tunnel-like in the sense that they have an interiorspace bounded by tissue, and openings positioned so that an anchor orother portion of a medical device may be passed through one opening,through the interior space of the tunnel, and out the other opening. Theinterior walls of the tunnel may lie in contact with one another,collapsing the interior space in the same way the space within a shirtis collapsed. In other embodiments, the tunnels may retain a moretubular shape.

Several such procedures rely in part on adhesion of the serosal tissuelining the outer surface of the stomach. It has been found that serosaltissue layers can adhere to form relatively strong bonds when held inapposition to one another.

For example, the tissue tunnels might be similar to the tunnels 28 shownin FIGS. 3A and 3B, or they might alternately be tunnels 28 a of thetype shown in FIGS. 3C and 3D created by forming holes 90 in serosaltissue plications 92. Methods for forming either type of tissue tunnelmay be carried out in a manner that takes advantage of the strongadhesions formed when serosal tissue surfaces are held in apposition.Other methods not specifically described herein may also be used withoutdeparting from the scope of the present invention.

FIGS. 8A through 8F illustrate one method of forming tissue tunnels(also referred to as tissue pockets) such as the type shown in FIGS. 3Aand 3B.

The orientation of the tunnels is chosen to best accommodate theparticular type of anchor/implant arrangement to be used. For example,tunnels may have an orad-aborad orientation as shown in FIG. 8F, or amore transverse orientation as in FIGS. 3A and 4A.

Referring to FIG. 8A, a rod 48 is positioned on the exterior surface ofthe stomach, and sutures 50 are attached to the rod 48 and passedthrough the stomach walls. The sutures 50 are drawn inwardly using anendoscopic grasper (not shown) to “tent” a section 52 of tissue of thetype shown in FIG. 8C. If desired, the method may be performed withoutthe rod 48 as shown in FIG. 8B, in which case a pair of sutures 50 a maybe passed from the stomach interior, through the stomach wall, and thenback into the stomach interior, and then drawn inwardly using anendoscopic grasper 54 to tent the tissue as shown in dashed lines.

Next, a line 56 of staples or sutures are applied across the tentedtissue from the mucosal side of the stomach—thereby forming an enclosedpocket 58 on the exterior surface of the stomach as shown in FIG. 8D.The rod 48 (if used) is enclosed within the pocket 58. Stapling/suturingmay be performed using an endoscopic stapler 60 a passed through theesophagus into the stomach, or using a laparoscopic stapler 60 bintroduced into the stomach through a surgical gastronomy site—both ofwhich are shown in FIG. 8C. The stapler/suture device preferably hascharacteristics that will form a suture/staple line 56 that issufficiently patent to seal the serosal tissue together to preventstomach leakage prior to complete serosal adhesion, but that ensuresgood blood flow so as to promote healing of the stapled tissue. Forexample, a conventional stapler modified to have a staple cartridge inwhich alternate staples have been removed may achieve this purpose.

A collar 62 may be placed around the tented tissue 52 as shown in FIG.8C prior to suturing/stapling so as to apply tension to the wall tissueto facilitate suturing or stapling.

The suture line 56 holds the serosal layers of tissue together as shownin FIG. 8E, thereby holding the pocket 58 together. The ends 64 of thepocket are cut, turning the enclosed pocket 58 into a tissue pocket ortunnel 28 having ends that open into the stomach interior. The rod 48,if used, is removed from the tunnel 28. The tissue preferably healstogether to form an adhesion that maintains the tunnel.

Because the tissue tunnel 28 is formed of serosal tissue, it may bedesirable to line the tunnel/28 with a stent-like device 68 or anotherliner to both reinforce and protect the serosal surface from the acidicstomach environment. Many of the embodiments described above rely uponformation of tissue adhesions between opposed tissue layers. The linermay also function as scaffolding that promotes tissue-ingrowth and/orfunction to reinforce the adhesions that form.

The procedure is repeated to form as many tunnels as are needed tosupport the desired number of anchor(s) in the stomach. Over time, theregions of tissue held in apposition will adhere together due to thebody's physiological or biological response, such as formation offibrous tissue or scar tissue, growth of new tissue, or a growing,healing, or knitting together of the opposed tissue layers. The term“adhesion” will be used in this application to refer to the adhering ofopposed tissue layers as a result of any physiological or biologicalresponse, including but not limited to those listed above.

To form tissue tunnels 28 a of the type shown in FIGS. 3C and 3D, aserosal plication 92 is formed. More specifically, tissue within thestomach interior is pinched together to draw serosal layers on thestomach exterior into contact with one another, thereby forming a foldedtissue tab or plication 92. A hole 90 is formed in the plication 92 andstaples 94 or sutures, etc., are placed around the hole 90 to keep thetissue pinched together until a serosal adhesion forms. Multipleplications 92 may be formed as shown in FIG. 3D.

Once the tunnels 28 (or 28 a) are formed, one or more anchor(s) 14 maybe coupled to the tunnels. In a preferred method, the tunnels areallowed to heal and then a later procedure is carried out to couple theanchors 14 to the tunnels and to position the implant 12. If desired,however, the anchors may be implanted during the same procedure in whichthe tunnels are formed, and the implant may then be positioned in alater procedure after the tunnels have healed. Naturally, tunnelformation, anchor attachment, and implant positioning may also beperformed in three separate procedures.

To implant the anchors 14, each anchor is passed through the esophagusand into the stomach, preferably under endoscopic visualization. Theanchor 14 and associated instruments may be passed down a sheathpositioned in the esophagus so as to protect the surrounding tissues. Aportion of the fastener 20 of the anchor is passed through the tissuetunnel 28, and the connectors 24, 26 are engaged to form the fastener 20into a loop as shown in FIG. 4A. An endoscopic grasper or other suitableendoscopic instruments may be used for this purpose. According to thefirst embodiment, a second anchor is coupled to a second tissue tunnelas shown. At this point, the loops 22 of the anchors 14 preferablyoverlap and are ready to receive the implant 12.

FIGS. 9A and 9B illustrate an alternative method for implanting anchors14 d. According to this method, anchors 14 d are attached to tissueplications 28 d formed in the stomach wall. Various methods for formingplications are described in WO 2005/037152, entitled “Devices andMethods for Retaining a Gastro-Esophageal Implant” published Apr. 25,2002. According to one method of forming a serosal plication, tissuewithin the stomach interior is pinched together (using an endoscopicgrasper, for example) to pinch serosal layers on the stomach exteriorinto contact with one another, thereby forming folded tissue tab asshown. A reinforcing patch 9 may be positioned between the serosaltissue layers. The patch may function as scaffolding that promotestissue—ingrowth and/or function to reinforce the adhesions that form.Sutures 11 (which may be bioabsorbable), pledgets 13, t-bars or otherfastening means are used to hold the tissue layers together at leastuntil adhesions bond the tissue layers together. These fasteners mayalso be used to attach the anchors 14 d to the plication as shown,although in an alternative method the anchors 14 d are coupled to theplications 28 d using sutures, staples or other fasteners after theplications have healed.

Eventually, adhesions form between the tissue layers (and through and/oronto the interstices of the patch) and serve to reinforce the bondbetween the tissue layers.

The patch may be a synthetic or non-synthetic mesh, porous material,slotted material, or any other material through which adhesions willform or onto which tissue will grow. Examples include, but are notlimited to, polypropylene, materials sold under the trade names Goretexor Dacron, or tissue graft material such as the Surgisis material soldby Wilson Cook Medical, Inc. The material may be treated withtissue-ingrowth promoting substances such as biologics.

FIGS. 15A through 15D illustrate another method in which the stomachwall may be re-shaped for retention of an implant. According to thismethod, a circumferential ridge of tissue may be formed around theinterior stomach wall, such as at the gastro-esophageal junction region,and the circumferential ridge may be used to retain the implant.Referring to FIG. 15B, a serosal plication may be formed by engaging aregion of the interior stomach wall using an endoscopic grasper 240,hook, pronged instrument, or similar device. By pulling the engaged wallregion inwardly, sections of external serosal tissue are drawn intocontact with one another to form serosa-to-serosal plication 242 (FIG.15D). With the plication engaged by the endoscopic instrument, a suture243, staple or other fastener is passed through the plication 242 asshown in FIG. 15B to retain the plication. A plurality of the plications242 are formed around the interior circumference of the stomach, thuscreating a circumferential ridge 244 of plicated tissue encircling thewall of the stomach. Over time, the opposed serosal layers form anadhesion. A restrictive implant 246 is then positioned in the stomach,proximally of the ridge 244.

Attachment of the implant 246 may be performed during the same procedurein which the circumferential ridge is formed, or at a later date topermit the adhesions to form before the ridge is subjected to thestresses that will be imparted against it by the implant.

FIGS. 16A through 16C illustrate a slightly modified method for usingserosal-to-serosal plication of wall tissue to form a circumferentialridge, and for securing an implant to the ridge. Referring to FIGS. 16Aand 16B, tissue is plicated using an endoscopic instrument 240 a whichincludes prong members 241. To form a plication, prong members 241 areused to pull stomach wall tissue in a proximal direction while a sutureneedle 243 or other fastening instrument advanced distally to drivesutures, t-bars, rivets or other fasteners downwardly into the plicatedtissue as shown in FIG. 16B. Force dissipating elements such as pledgetsmay be used to dissipate forces against the tissue surface.

Referring to FIG. 16C, a few (for example two to four) such plicationsare formed around the wall to form a circumferential ridge 244 a (FIG.16C).

Implant Positioning

FIG. 10A illustrates one method of mounting the implant 12 to the tool16 in preparation for implantation. In this figure, the implant wallsare shown as transparent so that the orad and aborad rings 36, 38 andthe waist ring 30 can be seen. In a preferred method, the implant isattached to the tool at three attachment points which fall at the oradring, the aborad ring, and the waist section. In alternative methods theimplant may be attached at different locations, such as only the aborador orad ends of the device, or elsewhere.

To mount the implant according to the method of FIG. 10A, a firstretention element such as nitinol wire 29 a is introduced into anopening at the open proximal end of the tool and passed distally throughthe lumen of the inner shaft 19. The distal end of the wire is thenextended through the distalmost one of the holes 27 c, through opening39 in the aborad ring 38, then inserted back into the lumen of the innershaft and returned to the proximal end of the tool 16 and may be markedand held together by a tab 41 c. The two ends of the wire 29 c areretained outside the tool. Similarly, a second nitinol wire 29 b ispassed down the annular space between the inner shaft 19 and the middleshaft 17, passed out of the middle shaft through one of the openings 27b, then through opening 31 in the waist ring 30 of the implant and backinto the annular space via the most proximal one of the openings 27 b.The ends of the wire 29 b are retained by a tab 41 b. This process isrepeated at the orad end of the implant to anchor the orad ring 36 usingnitinol wire 29 a. The relative positions of the shafts 15, 17, 19 areadjusted to place the implant 12 in the elongated position, and thenlocked in place.

Referring to FIG. 10B, once the implant 12 is assembled onto the implanttool 16, the tool 16 is positioned over the endoscope 18 by sliding theendoscope through the central lumen of the tool's inner shaft 19. Next,the distal end of the endoscope is passed orally into the esophagus, andthen through the loops 22 of the anchors 14 previously implanted. Theendoscope is retroflexed as shown in FIG. 10C, allowing the surgeon tovisually confirm that the endoscope has passed through both loops.

Referring to FIG. 10D, the implant tool 16 is advanced over theendoscope until the waist 30 of the implant 12 is adjacent to the loops22. The waist of the implant may be marked with identifying markers tosimplify this step of the procedure. Once the waist 30 is properlypositioned, release tab 43 a is depressed to allow the outer shaft 15 ofthe implant tool 16 is slide distally, causing the orad ring 36 to movecloser to the waist 30 thus expanding orad section 32 of the implant asshown in FIG. 10E. Once it is visually confirmed that the expanded oradportion of the implant is properly positioned, wire 29 a is withdrawn todisconnect the orad ring 36 from the implant tool 16.

Next, referring to FIG. 10F, the release tab 43 b is activated to allowthe inner shaft 19 to be withdrawn in a proximal direction, bringing theaborad ring 38 closer to the waist 30 and allowing the aborad portion 34of the implant to expand. Proper deployment is visually confirmed, andthen the wires 29 b and 29 c are withdrawn to detach the implant 12 fromthe tool 16.

Removal

FIGS. 11A and 11B illustrate one example of a method for removing theimplant 12. According to the method of FIGS. 11A and 11B, removal iscarried out using an extraction tool 72 comprised of a sheath 74 and ahollow rod 76 telescopically disposed within the sheath 74. Endoscope 18is slidable through the lumen of the hollow rod 76.

Sheath 74 includes a small side lumen 78. An elongate wire having a hook80 at its distal end is extendable through the side lumen 78 to deploythe hook 80 from the distal end of the sheath 74. Another hook 82 ispositioned on the distal end of the hollow rod.

Initially, the extraction tool 72 is arranged with the hollow rod 76fully withdrawn into the sheath 74, but with the endoscope 18 extendingdistally from the distal end of the sheath 74. The tool 72 is introducedinto the esophagus such that the sheath 74 is positioned proximally ofthe implant 12. The endoscope 18 is advanced through the implant 12 andretroflexed as shown in FIG. 11A to permit visualization of theprocedure.

Next, hook 80 is advanced through sheath 74 and manipulated to ensnare aretrieval loop 84 on the orad portion of the implant 12. Alternatively,the hook 80 may be used to grasp the orad ring 36 (FIG. 2) of theimplant. Once the orad portion of the implant has been engaged, hollowrod 76 is advanced to allow hook 82 to capture a retrieval loop 86 onthe aborad end of the implant 12 (or to capture the aborad ring 38). Thehollow rod 76 and sheath 74 are moved in opposite directions to elongatethe implant 12 as shown in FIG. 11B, and are then simultaneouslywithdrawn from the stomach (along with the endoscope 18) whilemaintaining the implant in the elongated position. Once the implant 12has been explanted, only the anchors 14 remain in place as shown in FIG.11C.

Alternative Configuration

FIG. 12 illustrates an alternative anchor 14 e which may be used tosupport an implant. Anchor 14 e may be a single component or multiplecomponents arranged to form a web-like structure in a gastro-esophagealjunction. As discussed with other anchor embodiments, the anchor 14 e ispreferably linked to tissue tunnels 28, although it may alternatively becoupled to serosal plications as discussed in connection with FIGS. 9Aand 9B, or it may be attached to the tissue in other ways.

Referring to FIG. 13, anchor 14 e may include a loop 22 e for receivingan implant 12 e as described above in connection with other embodiments.The implant 12 e may have an hourglass shape defined by a central waistsection as with implant 12 of FIG. 2, or it may be tapered as shown inFIG. 13. Referring to FIG. 14, the anchor 14 e may also be used tosupport an implant 12 f by simply preventing the implant 12 f fromdescending further into the gastrointestinal tract. For example, theimplant 12 f may take the form of a space occupying balloon that is notphysically attached or coupled to the anchor 14 e.

Implantation of the anchor 14 e may be accomplished using techniquesdescribed above. The implant 12 f may be positioned by coupling aninflation tube to an inflation port in the implant 12 f, and thenpassing the implant 12 f down a sheath positioned in the esophagus. Oncethe implant is within the stomach, the inflation tube is used to inflatethe implant 12 f, and is then detached from the implant and withdrawnfrom the body.

The implant 12 e may be implanted using a methodology similar to thatdescribed in the Implantation section.

Various components and methods have been described herein. Theseembodiments are given by way of example and are not intended to limitthe scope of the present invention. It will be apparent to personsskilled in the relevant art that various changes in form and detail maybe made therein without departing from the spirit and scope of theinvention. This is especially true in light of technology and termswithin the relevant art(s) that may be later developed.

It should be appreciated, moreover, that the various features of theembodiments that have been described might be combined in various waysto produce numerous additional embodiments. Also, while variousmaterials, dimensions, shapes, implantation locations, etc. have beendescribed for use with disclosed embodiments, others besides thosedisclosed may be utilized without exceeding the scope of the invention.For example, the anchoring methods and devices are not limited to usewithin the gastro-intestinal system and may be used for implants placedelsewhere in the body.

Any and all patents, patent applications and printed publicationsreferred to above are incorporated by reference.

1. An implant system, comprising: an anchor including a loop and a coupling device configured to couple the anchor to a tissue structure within a patient; and an implant device positionable within the loop.
 2. The implant system of claim 1, wherein the implant device includes a waist section positioned to seat within the loop.
 3. The implant system of claim 1, wherein the coupling device includes a free end extendable through a tissue tunnel defined by the tissue structure to couple the anchor to the tissue structure.
 4. The implant system of claim 1, wherein the coupling device is configured to couple the anchor to a tissue plication within a human stomach, and wherein the implant device is proportioned to slow the rate of passage of food into the stomach to induce weight loss in the patient.
 5. The implant system of claim 1, wherein the coupling device is configured to, couple the anchor to a tissue plication within a human stomach, and wherein the implant device is proportioned to significantly reduce the effective volume of the stomach to limit food intake by the patient.
 6. The implant system of claim 1, wherein the implant device includes a passage from a distal portion to a proximal portion of the implant device.
 7. The implant system of claim 1, wherein the coupling device is configured to couple the anchor to a tissue plication within a human stomach, wherein the implant device is mountable to an implantation tool, wherein the implantation tool is proportioned to extend from a mouth of the patient to position the implant device within the loop positioned within the stomach.
 8. The implant system of claim 7, wherein the implant device is expandable for engagement with the loop.
 9. The implant system of claim 8, wherein a proximal portion of the implant device is mountable to a first portion of the implantation tool, wherein a distal portion of the implant device is mountable to a second portion of the implantation tool, and wherein the first and second portions of the implantation tool are longitudinally moveable relative to one another to expand the implant device for engagement with the loop.
 10. The implant system of claim 1, further including a plurality of anchors, each including a loop and a coupling device configured to couple the anchor to a tissue structure within a patient, wherein the loops are positionable in the patient in at least partial alignment with one another and wherein the implant device is positioned within the at least partially aligned loops.
 11. The implant system of claim 10, wherein the implant device includes a passage and wherein the implant tool is extendable through the passage.
 12. The implant system of claim 7, wherein the implantation tool includes a lumen and wherein the system further includes an endoscope extendable through the lumen.
 13. The implant system of claim 1, further including instructions for use instructing a user to couple the anchor to a plication fondled in tissue and to insert the implant device into the loop of the anchor.
 14. The implant system of claim 1, further including instructions for use instructing a user to form a tissue tunnel by creating a serosal plication in stomach tissue, to couple the anchor to the tissue tunnel, and to insert the implant device into the loop of the anchor.
 15. A method of implanting a medical device, comprising the steps of: providing an anchor including a loop; coupling the anchor to tissue within a patient; and passing an implant device into the loop and retaining the implant device within the loop.
 16. The method of claim 15, wherein the tissue is within a human stomach.
 17. The method of claim 16, wherein the tissue is within a gastro-esophageal junction region.
 18. The method of claim 15, wherein the implant device includes a waist, and wherein the retaining step includes seating the waist within the loop.
 19. The method of claim 15, wherein the method further includes the steps of: forming a plication in body tissue, the plication defining a tissue tunnel; and extending a portion of the anchor through the tissue tunnel.
 20. The method of claim 19, wherein the anchor includes a fastener having first and second ends, wherein the coupling step includes extending the first end through the tissue tunnel and engaging the first and second ends.
 21. The method of claim 15, wherein the passing step includes mounting the implant device to a distal portion of an implantation tool and extending the distal portion of implantation tool from a mouth of the patient through the loop positioned within the stomach.
 22. The method of claim 21, wherein the retaining step includes expanding the implant device within the loop.
 23. The method of claim 22, wherein: the method further includes mounting a proximal portion of the implant device to a first portion of the implantation tool and mounting a distal portion of the implant device to a second portion of the implantation tool, and the expanding step includes longitudinally moving the first and second portions of the implantation tool relative to one another to expand the implant device.
 24. The method of claim 15, wherein the coupling step includes coupling a plurality of anchors to the tissue, each anchor including a loop, wherein the passing step includes passing the implant device through the loops and retaining the implant device within the loops.
 25. An implant device positionable within the stomach, the implant device including a proximal portion, a distal portion, and reduced-diameter waist portion disposed between the proximal and distal portions.
 26. The implant device of claim 25, further including a longitudinal passage extending through the implant device.
 27. The implant device of claim 25, further including instructions for use instructing a user to position the implant device at a gastro-esophageal junction region of a human stomach. 